The present invention is directed to an automatic icemaker of the type utilizing the energy of the fresh water supply to eject ice pieces from the mold cups of the icemaker.
Automatic icemakers are popular accessories for household refrigerators and numerous attempts have been made to simplify the design of the icemaker so as to reduce its cost. One of the problems associated with the design of automatic icemakers relates to the removal of the frozen ice pieces from the mold cups after they have been formed. U.S. Pat. No. 3,736,767 issued June 5, 1973 and assigned to the assignee of the present invention discloses a reversible mold employing a flexible bottom wall as the ice forming cup. After an ice piece has been formed in the mold cup, the mold is rotated 180.degree. and a fresh supply of water is entered into the empty, upward-facing receptacle. As the heat of the water warms the flexible wall the ice piece below is released and the flexible wall drops down to form a new cup for formation of a new ice piece. Although a useful concept, it nevertheless relies on the continued flexibility of the flexible bottom wall and as such presents a potential long term product service problem.
U.S. Pat. No. 2,941,377 issued June 21, 1960 is an example of the use of a contained charge of a volatile fluid, such as freon, in the mold. When heated by auxiliary means, the fluid vaporizes and causes a deformation of the ice forming cup to eject the ice piece. The structure disclosed is relatively complex and relies on the changing shape of the ice cup as the mechanism for ejection of the ice piece. It also has the objection of being quite noisy as the ejected ice pieces ricochet off an overhead deflector into the storage receptacle.
There is a need, therefore, for a simplified form of automatic icemaker with an inexpensive low cost form of ice ejection that is of long term reliability.